Background. The par­tic­u­lar bio­me­chan­ics of the ­upper cer­vi­cal ­spine ­require, ­when trau­ma ­occurs, care­ful eval­u­a­tion of the stabil­ity of the ­lesions, in ­order to guar­an­tee the ­best pos­sible ther­a­peu­tic and prog­nos­tic ­approach. To ­date, ­there has ­been no uni­for­mity of opin­ion in mer­it, espe­cial­ly ­with ref­er­ence to treat­ment of odon­toid frac­tures. It is nec­es­sary for ­this rea­son as ­much as for the oppor­tune stan­dar­disa­tion of the ­patients’ clas­sifi­ca­tion param­e­ters to estab­lish ­what is ­meant by stabil­ity and ­which ­lesions are to be ­held as ­being ­unstable in the ­upper cer­vi­cal ­spine. Methods. All the cas­es of ­upper cer­vi­cal ­spine instabil­ity treat­ed in our Unit ­from ’94 to ­date ­have ­been ­reviewed. Four frac­tures to the ­first cer­vi­cal ver­te­bra, 29 to the odon­toid pro­cess, ­9 iso­lat­ed frac­tures in the C2 ­body, ­12 hang­man frac­tures, 7 frac­tures of the artic­u­lar pro­cess­es, 2 to the occip­i­tal con­dyles and 4 C1-C2 dis­lo­ca­tions with­out frac­tures ­were loc­al­ised. Using pre­cise prog­nos­tic index­es as our clas­sifi­ca­tion cri­te­ria, 56 of the 58 ­patients ­observed ­were ­addressed ­towards ­either con­ser­va­tive treat­ment or direct­ly ­towards sur­gi­cal treat­ment. In par­tic­u­lar, 29 ­patients ­were con­ser­va­tive­ly treat­ed ­with a col­lar or Halo-Vest. Twenty-seven sur­gi­cal oper­a­tions ­were car­ried out: 14 ­screw fix­a­tions, 6 ante­ri­or fix­a­tions ­using ­plates and ­screws, 4 ­rear ­ones ­using met­al ­wire or ­wire ­with ­bone ­graft, 3 odon­tec­to­my oper­a­tions asso­ciat­ed ­with pos­te­ri­or fix­a­tion. Results. In the fol­low-up, ­using a ­range of ­between ­three ­months to six ­years, ­good ­fusion ­with ­spine sta­bil­isa­tion was ­achieved in all the ­patients treat­ed. In par­tic­u­lar, sur­gery was car­ried out as the ­first ther­a­peu­tic indi­ca­tion in 25 cas­es, obtain­ing excel­lent ­results. Surgery was nec­es­sary in ­only 2 cas­es ­after the fail­ure of exter­nal sta­bil­isa­tion. Conclusions. The judge­ment ­passed on instabil­ity in trau­mat­ic ­lesions in the ­upper cer­vi­cal ­spine rep­re­sents the deci­sive fac­tor in the ­choice of the ther­a­peu­tic ­option. Instead of ­always opt­ing for con­ser­va­tive treat­ment, in the ­case of C1-C2 frac­tures-lux­a­tions, and ­going ­ahead ­with sur­gery ­only ­when ­there is instabil­ity or non-­fusion of the seg­ments result­ing ­after suc­ces­sive mon­i­tor­ing, we ­believe ­that the def­i­ni­tion and stan­dar­disa­tion of the prog­nos­tic fac­tors is oppor­tune, in ­order to pro­vide ­patients ­with a spe­cif­ic solu­tion, in ­such a way as to ­reduce the fail­ure per­cent­age of the ­first treat­ment and optim­ise the heal­ing ­time.